Solar Collector Arrangement

This invention relates to solar energy. More particularly it relates to a solar collector arrangement. It further relates to a solar assembly.

The inventors are aware of solar collector arrangements which comprise a solar dish or reflector and a receiver which is mounted to receive concentrated radiation reflected from the solar dish. To this end, the receiver is mounted at a fixed position relative to the reflector which is typically coincident with the focal point of the reflector.

To optimise the harvesting of solar energy the reflector and receiver are secured together in a fixed spatial arrangement as an assembly which is typically mounted for angular displacement about vertical and horizontal axes to enable the reflector to follow the path of the sun.

In certain circumstances, e.g., in high wind conditions, the reflector and receiver assembly is displaced to a stowed condition in which the reflector faces downwardly and the receiver is positioned below the reflector. A problem with this arrangement is that this requires the reflector and receiver assembly to be mounted on a tower which is tall enough to ensure that when in the stowed condition the reflector is spaced far enough from the ground to provide sufficient clearance for the receiver to be positioned between the reflector and the ground. This results in substantial wind loading of the solar collector arrangement both when in its operative condition and in its stowed condition. In addition, construction costs are increased as a result of the height and strength of the tower required to support the reflector and receiver assembly.

It is an object of this invention to provide means which the Inventors believe will at least alleviate this problem or provide a useful alternative.

According to one aspect of the invention there is provided a solar collector arrangement which includes:

In the stowed condition, the spacing between the reflector and the receiver may be less than in the operative condition.

In the stowed condition, the wind loading on the solar collector arrangement may be less than in the operative condition.

The support arrangement may be configured to permit angular displacement of the reflector and receiver relative to one another between the stowed condition and the operative condition. To this end, the support arrangement may include a support structure to which at least one of the reflector and the receiver is pivotally connected by means of a pivotal connection for displacement about a first pivot axis between the operative and stowed conditions. In one embodiment of the invention, the reflector is pivotally connected to the support structure and the support arrangement may include an actuator whereby the reflector is displaceable relative to the support structure between its operative and stowed conditions. In one embodiment of the invention, the actuator may include a pressurised fluid operated piston and cylinder assembly. In another embodiment of the invention, the actuator may be electrically operated or alternatively a combination of hydraulic and electrical actuation. In yet another embodiment of the invention, the reflector is displaceable relative to the support structure by means of a torque tube which can be rotated, e.g., electrically, or hydraulically.

The solar collector arrangement may include a base which is rotatable about a vertical axis of rotation, the support arrangement being pivotally mounted on the base for angular displacement about a second pivot axis.

The first and second pivot axes may be parallel.

The support structure may include an elongate first support arm, one end of which is connected to the base, the receiver being mounted to the first support arm at or adjacent the other end thereof and a second support arm which is angularly spaced from the first support arm and to which the reflector is connected.

The reflector may be of composite construction and comprise a plurality of reflector elements. Each of at least some of the reflector elements may be parabolic in shape and have a focal point which is coincident with the receiver when the reflector is in its operative condition.

The receiver may be configured to heat a fluid. To this end, the receiver may include an inlet for receiving fluid to be heated and an outlet which is in fluid communication with the inlet, and through which heated fluid can be discharged from the receiver, in use.

In another embodiment of the invention the receiver may be configured to heat a solid.

According to another aspect of the invention, there is provided a solar assembly which includes:

The mobile platform may be in the form of a trailer which is disconnectably connectable to a draught vehicle.

The following description of the invention is provided as an enabling teaching of the invention. Those skilled in the relevant art will recognise that many changes can be made to the embodiments described, while still attaining the beneficial results of the present invention. It will also be apparent that some of the desired benefits of the present invention can be attained by selecting some of the features of the present invention without utilising other features. Accordingly, those skilled in the art will recognise that modifications and adaptations to the present invention are possible and can even be desirable in certain circumstances and are a part of the present invention. Thus, the following description is provided as illustrative of the principles of the present invention and not a limitation thereof.

Inof the drawings, reference numeralrefers generally to a solar collector arrangement in accordance with the invention. The solar collector arrangementincludes a reflector, generally indicated by reference numeral, a collector or receiver, generally indicated by reference numeral, and a support arrangement, generally indicated by reference numeral.

The support arrangementincludes a baseon which a turntableis mounted, the turntableincluding a topwhich is rotatable about an axis of rotationwhich extends vertically.

The support arrangementfurther includes a support structure, generally indicated by reference numeral, which is mounted on the topof the turntable. The support arrangementincludes an upright supportwhich is mounted on the topof the turntableand extends vertically upwardly therefrom. The support structureis pivotally connected to an upper end of the upright supportby pivot pinswhich permit pivotal displacement of the support structurerelative to the upright supportabout a horizontal pivot axis. The support structureincludes an elongate boomhaving a proximal end.and a distal end.. Further, the support structureincludes a reflector support armhaving a proximal end.and a distal end.. The proximal ends.,.of the boomand reflector support armare connected together such that the boomand reflector support armextend away from their connection perpendicular to one another. A pair of bracing or support strutsextend between the boomand support armto secure them together.

The receiveris mounted on the boomat or towards the distal end.thereof. The reflectoris connected by means of a pivotal connectionto the distal end.of the support armfor pivotal displacement about a horizontal pivot axis. Displacement of the support structurerelative to the upright supportabout the pivot axisis effected, in the embodiment shown, by means of a pressurised fluid operated piston and cylinder assemblywhich is connected to and extends between the upright supportand the boom. Alternatively, displacement of the support structurerelative to the upright supportabout the pivot axiscould be effected by means of an electrical actuator, e.g., a motor gearbox combination. Pivotal displacement of the reflectorrelative to the support structureabout the pivot axisis effected by a piston and cylinder arrangementwhich is connected to and extends between the reflectorand the support structure. Similarly, instead of the piston and cylinder arrangement, use could be made of an electrical actuator, e.g., a motor gearbox combination. As can be seen in the drawings, the connection of the piston and cylinder arrangementto the reflectoris at a position spaced from the connection of the pivotal connection of the reflectorto the support armto provide the requisite torque to displace the reflectoras described in more detail below.

It will be appreciated that one or more of the turntable, piston and cylinder assemblyand the piston and cylinder arrangementcould be replaced with an alternative drive arrangement such as a slew drive such as that available from Bearings Distributors (Pty) Ltd.

In the embodiment shown, the reflectoris a composite reflector and comprises a support frameto which a plurality of reflector elementsis connected at spaced apart positions. Each reflector elementis typically parabolic in shape and positioned such that a focal point of the reflector element is coincident with the receiverwhen the reflector is in the operative condition shown inof the drawings.

In the embodiment shown, the receiveris configured to heat a fluid. To this end, the receiverincludes an inlet for receiving fluid to be heated and an outlet which is in fluid communication with the inlet, and through which heated fluid can be discharged from the receiver, in use. Pipingis provided in order to feed fluid to be heated to the inlet and to feed heated fluid to a desired location, e.g., to be used as process heat or for power generation. In one application the heated fluid is used for the melting of metals, e.g., for processing, manufacturing or recycling. In another embodiment of the invention, the receiveris configured to heat up or melt a solid (direct or indirect heating of a solid piece or multiple pieces of metal for example).

In use, when the solar collector arrangementis in its operative condition shown inof the drawings, it is used in a conventional fashion and is displaceable about the vertical axis of rotationand the pivot axiswhich extends horizontally to follow the path of the sun and maximise the collection of radiation on the collector. Hence, inof the drawings, the sun would be relatively low to the horizon, e.g., early in the morning.

When it is desired to displace the solar collector arrangement into a stowed condition, e.g., during high winds and/or in low light conditions such as at night-time, the piston and cylinder arrangementis operated in order to displace the reflectorin the direction of arrow() about the pivot axisformed by the pivotal connection. As can be seen inof the drawings, the reflectoris displaced through approximately 90° from its operative condition (shown inof the drawings) to its stowed condition (shown inof the drawings). Naturally, to return the reflector to its operative condition, the reverse procedure is followed.

It will be appreciated that the total height of the solar collector arrangementis reduced substantially when in its stowed condition. In addition, the reflectorextends generally parallel to the ground thereby effectively decreasing the surface area of the reflectorwhich would be exposed to any wind loading. This could occur naturally, e.g., during high wind speeds conditions, rainstorms or the like. Besides minimising loading on the support structure during high wind speed conditions, the reflector stow feature also protects the sensitive reflector facets/elements from being damaged due to environmental exposure from above, e.g., during hailstorms, dust storms, or the like.

Another advantage with being able to place the collector in a stowed condition is that the reflector facets/elements face downwards towards the ground which allows for more effective cleaning and maintenance of the reflector elements.

Further, by virtue of the fact that the boomand receiverare not displaced together with the reflectorwhen displacing the reflector to its stowed condition, the height of the upright supportneed only be sufficiently high to provide clearance between the lowest edge of the reflectorand the boomand the ground during normal use. This reduced height of the solar collector arrangement when compared with prior art solar collector arrangements of which the Inventors are aware, once again substantially reduces wind loading on the solar collector arrangement both when in its operative and stowed conditions.

Reference is now made toof the drawings, in which reference numeralrefers generally to a solar assembly in accordance with the invention.

The solar assemblyincludes a mobile platform, generally indicated by reference numeraland a solar collector arrangement, generally indicated by reference numeral, mounted on the mobile platform.

In the embodiment shown, the mobile platformis in the form of a trailer comprising a wheeled chassishaving a hitchwhereby the traileris disconnectably disconnectable to a draught vehicle.

The solar collector arrangementwhich is mounted on the traileris similar to the solar collector arrangementshown inof the drawings and described above and, unless otherwise indicated, the same reference numerals used above are used to designate similar parts. The main difference between the solar collector arrangementand the solar collector arrangementis that the reflectorof the solar collector arrangementmakes use of fewer reflector elements. It will be appreciated, however, that depending on the intended application the reflector could include more or fewer reflector elements.

In the embodiment shown, the trailerincludes four telescopic legswhich can be deployed in order to stabilise the trailerwhen located at a desired position. It will be appreciated, that more or fewer legs could be used.

The solar assembly, with the telescopic legsin a retracted condition, can be transported to any desired location. At the desired location, the telescopic legsare extended such that they abut against the ground and support the trailerin a stable manner and such that the axis of rotationextends vertically. The solar collector arrangementcan then be used in substantially the identical manner to the solar collector arrangementdescribed above.

When it is desired to displace the solar collector arrangementinto a stowed condition, e.g., during high winds and/or in low light conditions such as at night-time, the reflectoris displaced in the manner described above into the stowed condition shown inof the drawings. When it is desired to return the solar collector arrangementto its operative condition, the reverse procedure is followed.

It will be appreciated, however, that in the stowed condition shown inof the drawings, the reflectorwill protrude laterally beyond the sides of the trailer. Accordingly, when it is desired to transport the trailer from one location to another, the solar collector arrangement can be displaced into a transport or second stowed condition, shown inof the drawings, in which the reflector extends generally longitudinally relative to the trailerand does not protrude beyond the edges of the trailer.

In this arrangement, the wind loading on the solar connector due to the movement of the trailer is also restricted which not only mitigates strain from wind speeds but also provides a compact profile that allows it to be transported on public roads.